Method and apparatus for full-resolution light-field capture and rendering. A radiance camera is described in which the microlenses in a microlens array are focused on the image plane of the main lens instead of on the main lens, as in conventional plenoptic cameras. The microlens array may be located at distances greater than f from the photosensor, where f is the focal length of the microlenses. Radiance cameras in which the distance of the microlens array from the photosensor is adjustable, and in which other characteristics of the camera are adjustable, are described. Digital and film embodiments of the radiance camera are described. A full-resolution light-field rendering method may be applied to light-fields captured by a radiance camera to render higher-resolution output images than are possible with conventional plenoptic cameras and rendering methods.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A camera, comprising: a photosensor configured to capture light projected onto the photosensor; an objective lens, wherein the objective lens is configured to refract light from a scene located in front of the camera to form an image of the scene at an image plane of the objective lens, wherein the objective lens is not focused on the photosensor; and a microlens array positioned between the objective lens and the photosensor, wherein the microlens array comprises a plurality of microlenses, wherein the plurality of microlenses are focused on the image plane and not on the objective lens; wherein each microlens of the microlens array is configured to project a focused microimage of a separate contiguous portion of the image of the scene formed at the image plane by the objective lens onto a separate region of the photosensor, wherein each separate region of the photosensor captures a plurality of contiguous pixels.
2. The camera as recited in claim 1 , wherein the microlenses in the microlens array are at a distance b from the photosensor, wherein f is the focal length of the microlenses, and wherein b is greater than f.
3. The camera as recited in claim 2 , wherein b is 4/3 f.
4. The camera as recited in claim 2 , wherein b is less than or equal to 1.5 f.
5. The camera as recited in claim 2 , wherein the camera is configured such that one or more spacers have been inserted between the microlens array and the photosensor to determine the distance b.
6. The camera as recited in claim 1 , wherein the microlenses in the microlens array are at a distance b from the photosensor, wherein f is the focal length of the microlenses, and wherein b is less than f.
7. The camera as recited in claim 1 , wherein the microlenses in the microlens array are at a distance b from the photosensor, wherein the camera is configured such that the distance b is adjustable.
8. The camera as recited in claim 7 , wherein the camera comprises an adjuster configured to adjust the distance b.
9. The camera as recited in claim 8 , wherein the adjuster is configured to adjust the distance b in response to user input to the camera.
10. The camera as recited in claim 8 , wherein the adjuster is configured to automatically adjust the distance b in response to detection of a change in an optical characteristic of the camera.
11. The camera as recited in claim 1 , wherein the photosensor is configured to capture a light-field image of the scene that includes each of the separate portions of the image of the scene projected onto the photosensor in a separate region of the light-field image.
12. The camera as recited in claim 11 , wherein the camera is configured to store the captured light-field image to a memory device.
13. The camera as recited in claim 12 , wherein the memory device is a component of the camera.
14. The camera as recited in claim 12 , wherein the memory device is implemented in a computing device separate from the camera.
15. The camera as recited in claim 1 , wherein the photosensor is a digital medium.
16. The camera as recited in claim 15 , wherein the digital medium is a charge-coupled device (CCD).
17. The camera as recited in claim 1 , wherein the photosensor is a film.
18. A method for capturing light-field images, comprising: receiving light from a scene at an objective lens of a camera; refracting light from the objective lens to form an image of the scene at an image plane of the objective lens; receiving light from the image plane at a microlens array located between the objective lens and a photosensor of the camera, wherein the microlens array comprises a plurality of microlenses, wherein the plurality of microlenses are focused on the image plane and not on the objective lens, and wherein the objective lens is not focused on the photosensor; receiving light from the microlens array at the photosensor, wherein the photosensor receives a focused microimage of a separate contiguous portion of the image of the scene formed at the image plane by the objective lens from each microlens of the microlens array at a separate region of the photosensor, wherein each separate region of the photosensor captures a plurality of contiguous pixels.
19. The method as recited in claim 18 , wherein the microlenses in the microlens array are at a distance b from the photosensor, wherein f is the focal length of the microlenses, and wherein b is greater than f.
20. The method as recited in claim 19 , wherein b is 4/3 f.
21. The method as recited in 19 , wherein b is less than or equal to 1.5 f.
22. The method as recited in claim 18 , wherein the microlenses in the microlens array are at a distance b from the photosensor, wherein f is the focal length of the microlenses, and wherein b is less than f.
23. The method as recited in claim 18 , wherein the microlenses in the microlens array are at a distance b from the photosensor, the method further comprising changing the distance b.
24. The method as recited in claim 23 , wherein said changing the distance b comprises manually inserting or removing one or more spacers between the microlens array and the photosensor.
25. The method as recited in claim 23 , wherein said changing the distance b comprises: receiving user input specifying a different distance b; and adjusting the distance between the photosensor and the microlens array to the specified different distance b.
26. The method as recited in claim 23 , wherein said changing the distance b comprises: detecting a change in an optical characteristic of the camera; and automatically adjusting the distance between the photosensor and the microlens array in accordance with the detected change in the optical characteristic of the camera.
27. The method as recited in claim 18 , further comprising capturing a light-field image of the scene at the photosensor, wherein the light-field image includes each of the separate portions of the image of the scene in a separate region of the light-field image.
28. The method as recited in claim 27 , further comprising storing the captured light-field image to a memory device.
29. The method as recited in claim 18 , wherein the photosensor is a digital medium.
30. The method as recited in claim 18 , wherein the photosensor is a film.
31. An apparatus, comprising: a camera comprising an objective lens, wherein the objective lens is configured to refract light from a scene located in front of the camera to form an image of the scene at an image plane of the objective lens; a film holder configured to hold a film and to be inserted into and removed from the camera, wherein the objective lens is not focused on the film holder; and a microlens array configured to be placed in the film holder against the film such that the microlens array is between the film and the objective lens of the camera when the film holder is inserted into the camera, wherein the microlens array comprises a plurality of microlenses on one surface, wherein the opposite surface of the microlens array is smooth glass, wherein the smooth glass surface is configured to be positioned next to the film, and wherein the plurality of microlenses are focused on the image plane and not on the objective lens when the film holder is inserted into the camera; wherein each microlens of the microlens array is configured to project a focused microimage of a separate contiguous portion of the image of the scene formed at the image plane by the objective lens onto a separate region of the film.
32. The apparatus as recited in claim 31 , wherein the microlenses in the microlens array are at a distance b from the film, wherein f is the focal length of the microlenses, and wherein b is equal to f.
33. The apparatus as recited in claim 31 , wherein the microlenses in the microlens array are at a distance b from the film, wherein f is the focal length of the microlenses, and wherein b is greater than f.
34. The apparatus as recited in claim 33 , wherein b is 4/3 f.
35. The apparatus as recited in claim 33 , wherein b is less than or equal to 1.5 f.
36. The apparatus as recited in claim 31 , wherein the microlenses in the microlens array are at a distance b from the film, wherein f is the focal length of the microlenses, and wherein b is less than f.
37. The apparatus as recited in claim 31 , further comprising one or more spacers configured to be placed between the microlens array and the film in the film holder to adjust the distance between the microlens array and the film.
38. The apparatus as recited in claim 36 , wherein the spacers are sheets of clear glass.
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November 14, 2008
June 14, 2011
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